Atomizing apparatus



April 12, 1932. HECHENBLEIKNER ATOMI Z ING APPARATUS Filed May 18, 1927INVENTOR lngenuln Hechen He} kne BY zToRNEYs Patented Apr. 12, 1932UNITED STATES PATENT, OFFICE INGENUIN HECHENBLEIKNER, OF CHARLOTTE,

TION OF DELAWARE u ATOMIZING APPARATUS Application filed Kay 18,

This invention relatesto improvements in atomizing or sprayingdevices,and more particularly to atomizing or spraying devices employable forthe atomization of liquids, slutions or suspensoids.

As is well known, atomization of liquids and solutions is employed inthe arts in various industries for producing finely divided solids orpowdered substances.

,When employed for ato'mizing true or suspended solutions atomization isusually accompanied by vaporization, and where it is desired to producea powdered substance from a liquefied state of such substance, theprocess is practiced without accompanying vaporization.

The improved atomizing or spraying apparatus of my present invention isgenerally applicable to atomizing liquids and solutions ,of varioussorts in theseindus- :0 tries.

One of the objects of the present invention is to provide an atomizingor spraying device which may be applied andemployed in the atomizing andspraying of all types of liquids and for all purposes. Where the objectis to obtain the finely divided, dry solid, the

atomizing or spraying is generally followed by treatment with hot orcold air. Hot air is usually used in su'ch cases where the liquid undertreatment contains solids therein, either in solution or in suspension.In such cases it is necessary to evaporatethe water or other liquid andin such cases the spraying device is disposed in a large chamber throughwhich hot air is passed for the purpose of vaporizing the liquid in thespray or mist formed in the chamber by the atomizing device and causingthe precipitation of a finely divided solid.

40 the production of dry milk or the atomization of various saltsolutions for the purpose of obtaining a salt in finely divided solidform.

I The present device may also be used in the formation of powdered soapand similar industries. In these processes the soap or other substanceis fed to the atomizing .device in its fluid or liquid state, and isthen atomized or sprayed into the chamber where it comes in contact withcold air which causes the fine- Examples of such cases are 1927. SerialNo. 192,464.

1y divided particles of liquid soap to solidify and precipitate infinely divided form.

The above uses of the present device are merely cited as illustrationsof the variety of uses and the variety of industries. in which thepresent device may beemployed, it being understood that these examplesare not to be considered as limitations upon the scope of the presentinvention.

The prime desideratum of the present invention is to provide anatomiz'ing device which will form -a uniform fine spray or mist.Broadly, the embodiment of the invention as disclosed in thisapplication comprises a rotating disc to which the liquid to be atomizedis supplied in the' form of a flowing stream. Discs, however, havealready been utilized for atomizing or spraying purposes.

that when a high de-'v It is found, however, gree of atomization isdesired, such discs must be rotated at extremely high speeds. In thepresent invention, however, the speed of the disc is reduced tocomparatively low its without interfering with the quality, ness oruniformity of the spray formed thereby. It is found that with the devicethat constitutes an embodiment of the present invention the range of ordesirable. falls second, the speed being varied in accordance with thecoarseness or fineness of the atomization desired. As will be explainedhereinafter, another element may be varied together with the variation1n speed to give variation in the size of the particles formed, and tomaintain their uniformity, the other factor entering into considerationbeing the length of the sloping sides of the discharge partitions orfins, which will be described more fully hereinafter. 4

As a concomitant of the reduction in speed of the device is thereduction in power consumption in the-operation of the device.

Another object of the present invention is to cause the disc tocooperate with the liquid under treatment in such a manner that beforethe liquid is permitted to leave the periphery of the disc it has fullyacquired the speed of the disc, and the centrifugal forces which enteras a factor in the atomization or spray- NORTHv CAROLINA, ASSIGNOR, BY-

peripheral speed necessary between 100-200 feet per.

ing of the liquid under treatment are utilized to the maximum capacity.The device is further so designed and constructed that this process ofimparting the high speed to the liquid is not accompanied by anysplashing.

The device is further so designed and constructed that in addition tothe centrifugal forces for the atomization of the liquid, air pressureis utilized to aid and assist in the process of atomization. This airpressure is inherent in the construction and operation of the devicewhich creates a substantial difference of pressure between the interiorand the exterior thereof. It is understood, however, that if desired anexternal source of air pressure may alsobe employed to assist thepressure head created by the operation of the atomizing head. It istherefore an object of the present invention to provide an atomizingdevice which utilizes the centrifugal forces due to rotation as well asthe atomizing effect of an air pressure head. The device is further soconstructed and designed that the air is caused to intimatelyintermingle with the liquid prior to the departure of the liquid fromthe periphery of the disc.

In the operation of various spraying devices known hitherto, difficultyhas been experienced due to the fact that solids are deposited on thedisc with the formation of a cake which throws theentire device out ofbalance and thereby shortens its life and increases the powerconsumption. In the present device this difliculty is entirely obviated.In other types of spraying devices known hitherto other difiicultieshave been experienced, due to the fact that the discharge open ings,usually of nozzle construction, clog or stop up in use by the deposit ofsolids in the discharge openings. This is generally due to the fact thatthe nozzle openings in order to obtain proper atomization, are usuallymade of small dimensions; and the clogging up in these small dischargeopenings is accentuated. by crystallization which takes place at suchopenings due to the hot gases surrounding the atomizing device. Thisobjection or difiiculty inherent in prior devices is obviated by meansof the present invention by the improved construction of the .sprayinghead which permits of comparatively large discharge openings to be used,and which further permlts the selective use of a cooling fluid whichprevents and minimizes crystallizing tendencies.

Other objects and advantages of the present invention will be apparentfrom the description of the construction and the operation of thedevice. i

The manner of attaining the above objects will be apparent from thedescription and the drawings, in which Fig. 1 shows a drying chamberhaving the spray forming device of the present inventioninstalledtherein,

Fig. 2 shows the construction of the atomizing head, and

Fig. 3 is a plan view of the atomizing head with one part partly brokenaway. I

In the drawings, reference numeral represents a spray drying chamberwhich is provided with openings 11 in its upper wall to shaft 17 of themotor 13 and is rotated thereby, the casing 15 from the head 12.

As shownin the drawings, the atomizing head 12 is of integralconstruction. It is obvious, however, that this is not a necessaryfeature of the present invention, and that, if desired, the atomizinghead 12 shown herein may consist of several parts separate in form andsubsequently assembled.

Specifically, the atomizing head 12 consists of the dished disc 18, theannular cover plate 19 and the fins or partitions 20 disposed in theannular space therebetween, the said fins or partitions 20 connectingsaid cover plate and said disk to form a peripheral wall, the saidperipheral wall being provided with the plurality of peripherallydisposed discharge openings '21. The side walls of the fins 2O definethe side walls of the openings 21. The dished face of the disc 18 isprovided centrally thereof with an upstanding hub 22 which is so shapedas to form the annular depression 23 having a curved face 24 shown incross-section in Fig. 2. I

One of the primary constructional features of the atomizing head 12resides in the deep 23 which serves to receive being but slightly spacedannular channel the stream of liquid 25 flowing from the feed pipe 16.The important feature of this phase of the construction is that thechannel is of such a depth that it is never completely filled by theliquid under treatment and serves as an air reservoir, whose functionwill be described presently. Another primary phase of the constructionof the present device is embodied in the fins or partitions 20. Thesefins or partitions, as shown, are preferably triangular incross-section, having their apiees directed towards the center of thedisc. The sidewalls" of each of the fins 20 thus slope inwardly(relatively to a disc radius common to the side walls) and towards eachother; and the said fins extend inwardly or radially from the peripheryof the disc only a short distance so that they are substantiallylocalized at the periphery of the disc; In the operation of theapparatus these fins or partitions act as the blades of a fan and causea suction of the air lodged in the annular channel 23 and thereby bringabout an air pressure head between the inner and outer ends of thedischarge openings. This causes an intimate intermingling between theair and the liquid under treatment-to take place within the dischargeopening which aids and assists materially in the atomization of theliquid. The size and shape of the fins or partitions may be varied withthe variation in the speed of operation of the apparatus. The lower thespeed of rotation of the atomizing head, the greater the radialdimension of the fins or partitions-and the smaller the slope of thesides of the fins or partitions.

As pointed out above, the annular channel 23 serves as a pocket for thelodgment of air which is drawn by the fan action of the fins or blades20 upwardly and outwardly in such a manner that the air interminglesthoroughly with the liquid in the discharge openings and thereby aids inthe atomization of the liquid. It should be noted at this point that thedisc 18 and the cover 19 are provided with annular horizontal faces 26and 2'? respectively whose radial dimension is the same as the radialdimension of the fins or partitions 20 and serve as the upper and lowerwalls for the discharge openings. The annular channel 23, in additiontoserving as a chamher for the lodgment of air, also serves to receive theliquid, the face 24 of the channel 23 being so shaped that the liquidentering from the pipe 16 andfed in the manner shown against the hub 22will join the surface of the rotating disc in such a manner that theliquid' will not splash. Furthermore, the upward slope 28 of theoperating face of the disc forces the liquid to flow upwardly with arotation of the disc, thus preventing thesplashing of the liquid andalso causing the liquid to'acquire the speed of the disc, so that by thetime the liquid will have reached the inner end of the dischargeopenings 21, the liquid will have acquired the speed of the disc and thecentrifugal forces resulting therefrom are fully utilized for theatomization of the liquid.

The air that is permitted to enter the spray head, as indicated bythearrows 29, may be hot air or cold air as desired and depending uponthe circumstances under which the anparatus is employed and dependingupon the type of material, and the treatment and the type of operationfor which'the apparatus is employed.

In such cases where it is desired to evaporate solutions to producepowdered products, as for example-in the production of dried milk and inthe vaporization of salt solutions for the purpose of producing a saltin powder form, cold air isdrawn into the spray head,

as indicated by the arrows 29. In the conduct of such processes hot airis drawn through the drying'chamber 10 with the consequence that withthe use of apparatus known hitherto, the spraying disc was heated and itfrequently happened that solid material was caked on the operating faceof the disc and some of the solids deposited within the dischargeopenings. By the use of cold air in the present apparatus, the disc, themetal immediately adjacent the dischargeopenings, as well as the liquid,while it is within the atomizer head, is cooled, and crystallization atthis point is thereby prevented.

' On the other hand, in the treatment of liqiud soap, namely soap in thehot and fluid state, for the production of dry powdered soap, or inother similar processes, hot air may be drawn into the atomizer headalong the path indicated by the arrows 29. In

such processes cold air is passed through thedrying chamber as indicatedby the arrows 30, the object being to reduce the temperature of the hotfiuid, finely divided soap in the chamber and thereby cause thesolidification thereof. The danger under such conditions is that thecold air may cause the solidification of the fluid soap at the dischargeopenings. In order to prevent this difiiculty from arising, hot air isdrawn into the atomizing head so that the fluid is maintained at thetemperature above solidification as long as it remains within theatomizing head.

When'the apparatus disclosed herein is employed to separate solidparticles which are suspended in the liquid, either hot or cold air maybe drawn through the atomizer as desired, for in-such case the problemsand difficultieswhich have been pointed out above "do not arise, thefunction of the air in such instances being limited to its assistance inthe atomization of the liquid so as to facilitate the vaporizationthereof and increase the efiiciency of the entire system.

It is to be understood that whether hot or cold air is drawn through theatomizer head, the amount of such air is small as compared with theamount of air that passes through the drying'chamber and will notmaterially affect the process of vaporization or solidification thattakes place within the chamber 10.

Under some conditions it may be desirable to drawthe atomizer airthrough the motor casing so that the air is preheated, the air alsoserving to cool the motor.

The upward and outward slope of the operating face of the disc 18 alsocooperates with the downwardly and outwardly sloping 'lid 19 to confinethe flow of air along the path indicated by the arrows 29 and directsame towards the discharge openings 21, and thereby cooperate with theoperation'of the fins or partitions 20 to bring aboutthe air pr'essurehead between the two ends of the discharge openings.

It should also be noted at this point that while the air drawn throughthe discharge openings is thoroughly intermingeld with the liquidflowing through said openings in the annular space formed by the faces26 and 27, the air passes out of said openings as indicated by thearrows 30 and further serves to increase the atomization of the liquidat points immediately adjacent to the periphery of the device due to thevelocity of the air as acquired in passing through the dischargeopenings.

In one embodiment of the present invention, the disc 18 has a maximumdiameter of 9", which when rotated gives a peripheral velocity varyingfrom 100 feet per second to 200 feet per second. In this form of thedevice, the partitions or fins 20 have. a radial depth of of an inch andtheir widest dimension is of an inch. When this embodiment of theinvention is rotated at a speed to give a peripheral velocity of 150feet a second, the resulting spray is of a high degree of subdivisionand uniform in nature. The finenesS of the particles obtained may bevaried by varying the velocity of the rotation of the device. The slowerthe velocity the coarser the particles. In order to obtain the same highdegree of uniformity, it is preferable that when the machine is designedfor reduced velocities, the radial depth of the fins should be increasedand the slopes of the sides thereof should be decreased. Highly uniformresults, however, are obtained by varying the velocity of the sameapparatus without necessarily varying the depth in slope of the fins.

It will also be apparent that while I have shown and described myinvention in the preferred form, many changes and modifications may bemade in the structure disclosed without departing from the spirit of theinvention, defined in the following claims.

I claim:

1. In an atomizing device, a rotatable disc having a hub disposedcentrally thereof and on its operating face, and having a relativelydeep annular channel surrounding said hub, means for feeding liquid tosaid channel tangentially of its face, anda plurality of triangularlyshaped fins arranged around and localized at the periphery of said headand spaced peripherally, to define discharge openings for said channel,the apices of said fins being directed inwardly. l

2. In an atomizing device, a rotatable disc, a lid for said disc andspaced therefrom and a plurality of partitions connecting theperipheries of said lid and said disc and dividing the space betweensaid lid and said disc into a plurality of discharge openings, eachpartition having its lateral walls sloping inwardiy and toward eachother.

3. 11 an atomizing device, a rotatable disc havin an upwardly slopingoperatin face, 7

a lid t erefor spaced from said discan sloping outwardly and downwardlyforming an annular space with said disc, discharge partitions disposedin said annular space. and having sloping sides localized at theperiphery of said disc, the slope of the sides being so related to thespeed of operation of the device that a uniform spray of a predetermineddegree of fineness is formed thereby.

4. An-atomizing apparatus comprising a rotatable atomizing head having acharge opening and having a peripheral wall provided with peripherallyarranged comparatively large discharge openings, the said head having arelatively deep annular channel having an operating face slopingupwardly toward the periphery of said head, and laterally arranged finshaving sloping side walls embodied in said rotatable head and localizedat the periphery thereof.

5. In an atomizing head, a rotatable disc, means for feeding hquid tosaid disc, a lid disposed over said disc and spaced therefrom to form anunobstructed annular space, said lid having an opening therein, andsubstantially radially arrange partitions localized at the periphery ofsaid ead connecting said lid and said disc to form a peripheral wall,said wall having a plurality of peripherally disposed dischargeopenings.

6. An atomizing device comprising a rotatable disk-shaped head, saidhead being provided with a plurality of triangularly shaped finsarranged around and localized at the periphery of said head and spacedperipherally'to define discharge openings therebetween, the apices ofsaid fins being directed inwardl 7. An atomizing device comprising arotat'able head, said head being providedwith a plurality ofperipherally arranged partitions, said partitions dividing theperipheral space of said head into a plurality of discharge openings,each partition having its lateral walls sloping inwardly and toward eachother.

8. An atomizing device comprising a rotatable disk-shaped head,discharge parti-' tions disposed in and localized at the peripheralspace of said head, said partitions having sloping sides, the slope ofthe sides of said partitions being so related to the speed of operationof the device that a uniform spray of a predetermined degree of finenessis produced in the operation of the device.

9. An atomizing device comprising a rotatable head, said headbeingprovided with substantially I radiall arranged partitions localized atthe perip cry of said head, saidpartitions forming a peripheral wall,said peripheral wall having a pluralityof peripherallydisposed dischargeopenings.

10. An atomizing device comprising a rotatable head, partitions disposedin the petoo ripheralspace of said head, the spaces between saidpartitions definin discharge openings and the side Walls of saidpartitions forming the side walls of said openings, the adjacent sidewalls of contiguonsly arranged partitions being directed relatively toeach other so as to define converging discharge openings.

Signed at Charlotte, in the county of Mecklenburg, and State of NorthCarolina,

this 16th day of May A. D. 1927.

INGENUIN HECHENBLEIKNER.

